不同脂肪酸钙对奶牛血液生化指标的影响

[目的]研究3种不同的植物油脂肪酸钙对奶牛血液生化指标的影响。[方法]选取24头处于泌乳前期的中国荷斯坦奶牛,采用配对分组设计分成4组。分别在基础日粮中添加200 g棕榈油脂肪酸钙、200 g大豆油脂肪酸钙、200 g葵花籽油脂肪酸钙。预饲期15 d,试验期45 d。于正试期分别测定4组奶牛血液各项生化指标。[结果]日粮中添加棕榈油脂肪酸钙后,奶牛血糖含量提高7.15%、血浆尿素氮降低2.09%、血浆β-羟丁酸含量降低16.68%、血清非酯化脂肪酸含量降低20.64%;添加大豆油脂肪酸钙后,奶牛血糖含量降低2.78%、血浆尿素氮含量增加18.17%、血浆β-羟丁酸含量降低15.42%、血清非酯化脂肪酸含量降低5.86%;添加葵花籽油脂肪酸钙后,奶牛血糖含量降低0.98%、血浆尿素氮含量增加4.26%、血浆β-羟丁酸含量降低30.36%、血清非酯化脂肪酸含量提高6.00%。[结论]日粮中添加3种不同的植物油脂肪酸钙,均能降低奶牛脂肪组织的动员,有效缓解奶牛能量负平衡。     

Uncoupling of an epithelial cell membrane junction by calcium-ion removal

Calcium takes part in maintaining ion communication between salivary gland cells (Chironomus thummi). Its withdrawal from the cell systems results in virtual disconnection of ion communication, at Ca(++) concentrations which do not noticeably affect cell adhesion. The junctional membrane surfaces. which are normally quite freely permeable to ions, become as impermeable as the nonjunctional membrane surfaces; each cell seals itself off irreversibly as a unit. In maintaining ion communication Mg(++) substitutes for Ca(++)     

Effects of veratrine and cocaine on cerebral carbohydrate-amino acid interrelations

The rate of aerobic transformation of glucose-U-C(14) into radioactive amino acids by slices of rat-brain cortex is greatly influenced by the K(+)/Ca(++) ratio in the incubating medium. Protoveratrine has effects on the amino acid pattern resembling that due to an increase in the K(+)/Ca(++) ratio. These effects are antagonized by cocaine and may be correlated with the neurophysiological activities of these drugs.     

Tetrodotoxin and manganese ions: effects on electrical activity and tension in taenia coli of guinea pig

Tetrodotoxin, at concentrations up to 5 x 10(-6) gram per milliliter, has no effect on the spontaneous discharge in the smooth muscle of taenia coli. However, the spontaneous discharge is abolished by Mn(++) at a concentration of 0.5 millimole per liter. The contraction induced by immersing the muscle in isotonic KCl solution is also suppressed in the presence of Mn(++). Because Mn(++) is a specific suppressor of the spike induced by Ca(++) and tetrodotoxin is an inhibitor of the spike induced by Na(+), we suggest that Ca(++) is a charge carrier in the production of spike potential in the smooth muscle and that the entry of intervening Ca(++) through the membrane acts as a trigger for the contraction of smooth muscle.     

Uncoupling of a nerve cell membrane junction by calcium-ion removal

Calcium ion participates in maintaining electrical connections between the nerve cells of Retzius (Hirudo medicinalis). The conductance across the junction between these cells decreases with decreasing concentration of free, extracellular Ca(++) At a certain level of Ca(++) withdrawal from the cell system, junctional conductance reaches a critical low point at which the cells become functionally disconnected: the nerve impulses which are normally discharged in synchrony by the cells become asynchronous. These effects of Ca(++) on junctional connection are irreversible, in contrast to those on nonjunctional surface membrane permeability.     

Phosphate Glass Electrode with Good Selectivity for Alkaline-Earth Cations

A phosphate glass has been found to have a significant electrode specificity toward alkaline-earth ions. The order of selectivity is 2H(+) > Ba(++) > Sr(++) > Ca(++) > 2K(+) > 2Na(+) > Mg(++). Exchange properties are discussed in relation to possible structure. Its use to determine activity of Ca(++) in natural systems containing Mg(++) is sug gested.     

pH值和碳酸钙对不同形态磷酸盐有效性的影响

本文研究结果,在培养液为ｐＨ６．５,７．５,８．５条件下,Ｃａ２－Ｐ,Ｃａ８－Ｐ和Ｃａ１０－Ｐ处理均随溶液ｐＨ值降低其速效磷含量增加,而Ｆｅ－Ｐ和Ａｌ－Ｐ则随溶液ｐＨ值降低而减少,加入ＣａＣＯ３,各形态磷酸盐有效性明显降低,且ｐＨ值越低下降幅度越大,小麦幼苗对各形态磷酸盐的吸收量均随溶液ｐＨ值降低而增加,当ＣａＣＯ３存在时,小麦幼苗对磷的吸收明显降低,随溶液ｐＨ值的升高,加ＣａＣＯ３与不加处理间差     

卵黄、牛奶及EDTA对冷冻过程中猪精子内Zn~(++)和Ca~(++)含量的影响

冷冻过程中,卵黄能有效地抑制精子内Zn~(++)含量的升高,而牛奶则无此作用。由于卵黄和牛奶中都含有大量的Ca~(++),因此当用作保护剂时,会使冻后精子内Ca~(++)的含量大大升高,但卵黄的影响较小。如果在卵黄中加入EDTA,则能明显阻止精子内Ca~(++)含量的升高。而且,解冻后精子的存活时间也延长。试验结果表明:(1)卵黄对精子的保护作用优于牛奶;(2)卵黄和牛奶中的Ca~(++)会影响解冻后精子的存活,但添加EDTA后可得到明显改善。     

不同添加剂(物)对玉米秸秆青贮有机酸含量的影响

以玉米为原料,添加碳酸钙、尿素、玉米籽实、麸皮、青贮发酵益生菌(Max200)、矿物盐载体结合益生菌合剂以及植物细胞壁降解活性制剂(MixⅡ),通过测定青贮发酵期有机酸含量,评价不同添加剂(物)对青贮效果的影响.结果表明:全贮(全株玉米)中,在发酵期第1、7、14、21d添加MixⅡ组和Max200组乳酸含量均极显著高于其他处理组及对照组(P<0.01),添加MixⅡ组乳酸含量显著高于Max200组(P<0.01);黄贮(摘除果穗)中,在发酵期第1、7、14、21d添加MixⅡ组和Max200组乳酸含量极显著高于其他处理组及对照组(P<0.01),第7、21d添加MixⅡ组乳酸含量显著高于添加Max200组(P<0.01).青贮第21d,添加麸皮组、尿素组、碳酸钙组、Max200组、MixⅡ组和对照组乳酸与乙酸的比值在全贮中分别达到1.93、2.36、1.60、3.74、3.64、2.13,黄贮中分别为1.53、2.25、1.98、2.54、3.11、1.33,添加MixⅡ组和Max200组显著高于其他处理组(P<0.01).发酵期第14d和21d,仅在全贮和黄贮个别样中检测到微量丁酸.     

山东潮土高产农田的供磷特性

潮土表层土壤中全磷以无机磷为主,无机磷中以Ca—P为主,Ca—P中又以Ca10-P为主,有机磷中以MLOP（中度活性有机磷）含量最高;灰色关联分析结果表明,潮土中的Ca2-P、A1-P、Ca8-P和LOP（活性有机磷）的相对有效性较高。潮土吸附和固定的主要基质是物理性粘粒,其次是CaCO3;解吸则主要受物理性粘粒的影响。潮土的3种磷酸化酶以碱性磷酸化酶的活性最高;有机解磷细菌数量大于无机解磷细菌数量,土壤微生物转化有机磷强度大于转化无机磷强度。高产农田的有效磷、缓效磷、Ca2-P含量均极显著高于中低产田,有机质、A1-P、供磷强度均显著高于中低产田;3种磷酸化酶的活性、解磷细菌数量和土壤微生物转化有机磷和无机磷强度,高产田均高于中低产田;高产农田比中低产田对磷的吸附能力强,固磷能力差异不显著,对吸附磷的解吸较易。     

树莓酒不同降酸工艺研究

树莓在我国是一种新兴水果,具有较好的鲜食和加工价值。通过采用CaCO3、KHCO3、K2C4H4O6、复盐法等6种不同降酸方式,分析比较了不同降酸方式的降酸效果及对酒的质量的影响。结果表明：采用KHCO3降酸,能较容易达到树莓酒降酸的要求,但如果用量过大,会使酒体略微表现出苦涩味;利用CaCO3处理,能达到树莓酒降酸目的,而且可以保留原有的香气和口感,但热稳定性差,需要结合离子交换树脂去除Ca2＋;利用K2C4H4O6降酸,用量大,成本高,且易生成KHC4H4O6,清除较麻烦。     

Impact of anthropogenic CO2 on the CaCO3 system in the oceans

Rising atmospheric carbon dioxide (CO2) concentrations over the past two centuries have led to greater CO2 uptake by the oceans. This acidification process has changed the saturation state of the oceans with respect to calcium carbonate (CaCO3) particles. Here we estimate the in situ CaCO3 dissolution rates for the global oceans from total alkalinity and chlorofluorocarbon data, and we also discuss the future impacts of anthropogenic CO2 on CaCO3 shell-forming species. CaCO3 dissolution rates, ranging from 0.003 to 1.2 micromoles per kilogram per year, are observed beginning near the aragonite saturation horizon. The total water column CaCO3 dissolution rate for the global oceans is approximately 0.5 +/- 0.2 petagrams of CaCO3-C per year, which is approximately 45 to 65% of the export production of CaCO3.     

NO^—2与水稻幼苗N素化合物代谢的关系

以水稻幼苗为材料，在水培条件下研究了ＮＯ＾－２水与稻Ｎ素化合物代谢的关系。结果表明，随ＮＯ＾－２浓度增加，地上部和根中的ＮＯ＾－２浓度增加，地上部和根中的ＮＯ＾－２含量上升，随着时间延长，ＮＨ＾４－Ｎ含量增加；Ｆｅ＾＋＋可降低ＮＯ＾－２－Ｎ含量，促进ＮＨ＾４－Ｎ积累。施ＮＯ＾－２Ｎ时秧苗中的天门冬氨酸，谷氨酸，内氨酸含量高，而根中天门冬氨酸，谷氨酸含量较低；结构性蛋白，叶绿体蛋白，细胞质白含量...     

新型营养添加剂纽甜-钙螯合物的合成

[目的]合成纽甜-钙螯合物,对其结构进行表征,并对其合成工艺进行优化。[方法]以纽甜和CaCO3为原料合成纽甜-钙螯合物,运用正交试验对螯合物的合成条件进行优化;通过元素分析、红外光谱、热重分析、粉末衍射对螯合物结构进行表征。[结果]最佳的合成工艺条件为n（纽甜）∶n（CaCO3）1∶2,反应温度90℃,反应时间3 h。纽甜与微量元素钙成功配位,且晶型良好,螯合物中钙的含量约为9.20%,推断其组成为Ca（C20H30N2O5）.H2O。[结论]该研究为纽甜-钙螯合物的合成提供了一种高效的方法。     

苹果膜脂脂肪酸与冻害关系的研究

苹果枝条皮部所含膜脂脂肪酸的种类相同,主要有亚油酸(18∶2)、亚麻酸(18∶3)和软脂酸(16∶0),其次是油酸(18∶1)和硬脂酸(18∶0);但不同品种脂肪酸种类配比各异.各种脂肪酸的克分子百分比含量随着季节的变化而变化,不饱和度高的脂肪酸(18∶2和18∶3)在冷凉和寒冷的季节中明显高于温暖季节,而饱和脂肪酸(16∶0和18∶0)和饱和度低的脂肪酸(18∶1)则与此完全相反.另外,不饱和脂肪酸的克分子百分含量与苹果的冻害级别(抗寒力)显著相关,因此膜脂不饱和脂肪酸的克分子百分比含量可以作为抗寒力鉴定的指标.     

补饲CaCO3对猪肉系水力的影响

选用体重相近(85 kg左右)的杜长大三元杂交猪20 头,随机分成5组,其中1组为对照组,饲喂基础日粮,其余4组为试验组,分别在基础日粮的基础上每日补饲CaCO37.5或15.0 g,连续补饲5或10 d即屠宰.通过对滴水损失、煮熟率的测定来评价补饲CaCO3对猪肉系水力的影响.结果显示:补饲CaCO3不影响各部位猪肉的滴水损失和熟肉率(P＞0.05),即不影响猪肉的系水力.     

Participation of an intermediate of oxidative phosphorylation in ion accumulation by mitochondria

Heart mitochondria accumulate massive amounts of Mg(++) and phosphate or Ca(++) and phosphate when incubated under appropriate conditions. Studies with inhibitors of respiration, oligomycin, and uncouplers of oxidative phosphorylation indicate that the energy necessary for these reactions may be provided either in the form of ATP in the absence of electron transport, or in the form of a high-energy intermediate of oxidative phosphorylation, which operates even though ATP is not produced.     

盐碱化土壤的两种提取液研究

对盐碱土的两种提取液的阴、阳离子的测定值，应用推理计算法，揭示了饱和提取液到５：１提取液之间发生的一系列定量的化学过程和物理化学过程。对这批土样，即ＣａＣＯ３、ＣａＳＯ４、ＭｇＣＯ３的溶解；溶液中的Ｃａ＋Ｍｇ与胶体上的交换性Ｎａ之间的交换反应；还有负吸附效应。     

The role of Mg2+ as an impurity in calcite growth

Magnesium is a key determinant in CaCO3 mineralization; however, macroscopic observations have failed to provide a clear physical understanding of how magnesium modifies carbonate growth. Atomic force microscopy was used to resolve the mechanism of calcite inhibition by magnesium through molecular-scale determination of the thermodynamic and kinetic controls of magnesium on calcite formation. Comparison of directly measured step velocities to standard impurity models demonstrated that enhanced mineral solubility through magnesium incorporation inhibited calcite growth. Terrace width measurements on calcite growth spirals were consistent with a decrease in effective supersaturation due to magnesium incorporation. Ca(1-x)Mg(x)CO3 solubilities determined from microscopic observations of step dynamics can thus be linked to macroscopic measurements.     

几种磷矿粉中磷和钙溶出动力学特性

采用间歇实验方法,研究4种磷矿粉在1M NH4OAc(pH4.8)酸性溶液中磷和钙溶出动力学规律,结果表明:磷矿粉中磷的溶出分为2个阶段,0～30min为快反应过程,30min后为慢反应过程,它能较好地符合Elvoich方程,磷的溶出速率(b)与枸溶性磷含量有较好的相关性,主要受磷矿粉中SiO2和碳酸钙含量的影响,枸溶性磷含量愈高,磷的溶出速率愈大,溶出磷的浓度也愈高。磷矿粉中钙的溶出也符合Elvoich方程,且与游离的碳酸钙含量有关,与其他磷矿粉不同,在PR1中钙的溶出浓度较高,很可能来自于碳酸钙的溶解。因而,磷矿粉不仅可以提供磷素营养,还提供植物生长所需的钙素营养。